Dual purpose pickup assembly and relief member therefor



Oct. 23, 1951 B, N, HSHER 2,572,712

DUAL PURPOSE PICKUP ASSEMBLY AND RELIEF MEMBER THEREFOR Filed NOV. 6,1948 INVENTOR. 5501/6 /v. 1 75/7 56 I WM/MQ Patented Oct. 23, 1951 I-TEDSTATES PAT QEEICE;

DUAL PURPOSE PICKUP ASSEMBLYAND- RELIEF MEMBER THEREFOR BerneNaFisher,Roselle, N. .L, zass ignon to Gen-- eral InstrumentCorporation, Elizabeth, N. J a corporation of New J ersey ApplicationNovember 6, 194=8-','-SerialN(.\ 58;8 l5

13 Claims.- (Cl. fi l-24) The present invention relates to a pickupassembly suitable for: use: with difierenttype records, saidassemblycomprising, in a single tone arm,.a plurality of pick-uprunits and arelief member adapted" toengage the'top of a record so. as to decrease:the force :exerted on the record by the stylus orneedle. associatedwith one, of thepick-uptunits;

This inventiomhaszi particular applicability to the production: of; apick-up assembly suitable for use with conventional recordsand alsosuitable? for: use with: the new" long playing records. Records, oftheconventional type; whether their diameter: be of'l0ror l2'inch,are=:normal1y rotatedatapproximatelyflB-R. P; M. The grooves inxsuchrecords-area normally, of a width such that the diameter 'of theatip" ofthe needle used to' reproduce.- such: records is. approximately, 3 mils.Longplayingmecords are rotated at approximately: 33.- R; PLM; and ':thegrooves of such recordsJaremuch more closely spaced,.in order to provide'for an exceedingly long playing time for agiven size'record; Asaresult, needles capabl'e: of: reproducing such longsplayin records musthave a: tip: diameter: of no more" than approximately 1: mil:Consequently, needlessuitable: foruse-withconventional records cannotbeused with. long; playing; records. While it would be possibleyif;reproduction of long playing records is"desiredafter'reproduction ofconventional records -has=been. achieved, to replace theconventionalneedle with a needle suitable for use with" the: long;playing; records, this is normally a delicate: operation: and at bestwould be veryg'time consuming and "bothersome. More-- over, with.permanent needles of extremely long life, ,removal of those needles frompick-upunits is most undesirable once they have been: clampedin-position therein, since if they are removed and, replaced,- they.will probably not be replaced in an. alignment exactly correspondingwith their previous" alignment and as a result the sides: of the recordgrooves willbe severely abraded, thus-.cuttingdown record life;

Therefore'iromtar-practicalcommercial point of view, it is necessary, ina record reproducing, unit-which is' capable of reproducing bothconventionaLand longgplayingi records, toprovide a .pairof pick-i-up:units-.01 cartridges each moreor less permanently associated with itsown. needle and each suitable for. playing a partice ularxtype. of=record.- While it is conceivable that. an; apparatus. might .be madewith two separate tone arms,-one for each type of record, suchasolutionlof theproblem-is=quite impractical since 2; it involves aconsiderable increaseinlweight in materialv employed; anddifliculty ofoperation, since :each :toneuarin' wouldhave :to. have. its:-

own mounting; Notonlyz wouldxthis prove=ex-.-- ceedingly: expensive, butit. would: also render; impractical the employment ofautomatic-rem: ordchangers useable with:both:=types ofrecords; since two tone arm movinmechanisms :would: have to be provided, each one operative: only whenitsassociatecltone arnr is'sbeing; employed for reproduction.

The best solution from. all pointssof view is:

to employa. single tone arm-and to embodm therein a pairofplick-uriunits,- oneuseableewith. each type of record; thepickup; unitsbeing; movable one: at. a: time into operative. or; repro.-- ducing.position.v However,-, here'wanotherl prob-- lem must be consideredOptimum. reproduce tion of standardrecords is achieved whe'n the: forceexerted zby the needleron thewrecord is'zon the orderto tol fi ounces".Since thetone. arm and the-pick-upynnittweigh more than this; it iscustomaryto counterbalancerthetone armso that the force; exerted by, theneedle is; of the proper. value. Onlthe other. hand, optimumreprodu'ctionloi long playing gIBCOI'dS is achieved when the. force.exerted by the needleiis consideerably, less,. on the-orderu of A.; to./;10111106; Exertion of greater force will resultlin excessive: wearontherecord; thus; reducing its life, and in distorted reproduction...

A- correlative problem :resides: in the fact. that: if the narrower longplayingy. record. needle: be employed with conventional records; the:narerowness 20f the needle will cause: aawearingf-awan of a the record"surfaceeandlawveryg rapid deteriora== tion of the'reproduceabilitythereof;

Consequently; when a single: tone arm 1S1 employed. to be used with.both. types: of records? some mechanism must be? provided for varyingthe force exerted: on therrecordbytheztneedlee dependin upon'the typeof; needleandthe type of record. It is possible tohaveravariable coun.terbalancing arrangement controlledlby the: po..-- sition of the pickupunits.-so.-as toprov-ide more counterbalancing; when thewpickeup unitfor long playing records is in operative-positiom However, thisW0111d.b6 a. rather. expensive. matter involving, relatively complicatedmechanical arzrangements.

Because of the. very! slight forceexerted-by' the needle.- on) the-long;playing record, and be. cause of the-finenessof;. the: grovesin. a:long; playingrecord, reproduction-2ofrlongplaying rec ords is a--relativel r; criticaLmatter insofar as.

vibration and shock are concerned, since the pick-up unit has a. markedtendency to slide or skate over the top of the record when subjected toany external force. Damage to the record can result therefrom, but moreimportantly, reproduction of a part of the record will be skipped; Inaddition, because of the slight tracking force exerted on the needle bythe fine grooves of long playing records, tone arms associated therewithquite often will not move into the terminal grooves thereof and henceconventional types of automatic record changer tripping mechanism eitherof the velocity or position type are not useable with any degree ofcertainty.

It is the prime object of the present invention to devise a pick-upassembly in a single tone arm which is capable of use both withconventional and long playing records, which automatically achieves thecorrect needle-record force, and which is fool-proof in operation.

Yet anothe prime object of the present invention is to devise anadjustable relief member associatable with a tone arm, said memberengaging the top surface of a record and thus controlling the forceexerted by the needle on the record, the resilience of the relief memberbeing adjustable so as to; render the needle-record force adjustable.

Yet another object of the present invention is to devise a pick-upassembly comprising a pair of pick-up units with associated needles, onesuitable for reproduction of a conventional record and the othersuitable for reproduction of a long playing record, the latter havingassociated therewith a resilient relief member engageable with the uppersurface of a record when the latter unit is in operative position so asto reduce the force eX- erted by the needle on the record to its propervalue, the tone arm being counterbalanced or otherwise constructed so.that when said resilient relief member is'notin record engagingposition, the force exerted by a needle on a record will be suitable forconventional records.

=i Yet another object of'the present invention is to devise a resilientrelief member which not only controls the needle-record force but whichalso assists in the tracking of the pick-up assembly on the record. 7

' To the accomplishment of the foregoing objects and such other objectsas may hereinafter appear, the present invention relates to a, dualpurpose pick-up assembly and to a resilient relief member adapted to beused in conjunction therewith as defined in the appended claims and asdescribed in this specification, taken together with the accompanyingdrawings, in which:

Fig. 1 is a side view, partially in cross-section, of thepick-upassembly of the present invention; 7 Fig. 2 is a view similar toFig. 1 but showing the parts thereof in another position;

' Fig. 3 is a schematic view, partially in crosssection, showing theconstruction of the resilient relief member;

i Fig. 4 is an end view of Fig. 1; and I Fig. 5 is a view similar toFig. 3 but showing an alternative construction.

' The pick-up assembly of the present invention comprises'a tone armgenerally designated A in which a pair of pick-up units Band C aremovably mounted. These pick-up units B and C may take any conventionalform, maybe either of the magnetic, capacitive, crystal, o any othertype; and are: here shown merely schematically. A resilient reliefmember D isalso provided and so positioned as to be operativelyassociated with that one of the pick-up units, designated in thedrawings by the letter C, which is to be used for reproduction of longplaying records. A moving mechanism generally designated E is providedfor moving the pick-up units B and C and the relief member D between twoplacements in one of which the pick-up unit B is out of operativeposition, the pick-up unit C is in operative position and the reliefmember D is in record engaging position (see Figs. 1, 3, 4 and 5) and inthe other of which the pick-up unit B is in operative position, thepick-up unit C is out of operative position and the relief member D isout of record engagement position (see Fig. 2).

As an optional but very desirable feature, a means F is provided foradjusting the resilience of the relief member D and thus controlling theforce exerted on a record, by the needle associated with the specialpick-up unit C.

As here specifically disclosed, the tone arm A is of conventional form,comprising a U-shaped' metal shell 2 having side walls 3 and an end wall4. The tone arm A may be mounted on the reproducing apparatus in anyconventional manner. A U-shaped bracket 6 is secured in the tone arm Aas by means of the screws 8 receivable in bosses It], a supportgenerally desig-- nated 2 for the pick-up units B and C being pivotallymounted between the depending arms I4 and R6 of the bracket 6.

The support 12 may comprise a flat sheet I8 having a portion 20 ofcircular cross-section projecting therefrom, the pick-up unit B beingsecured to the sheet IS on one side thereof and the pick up unit C beingsecured thereto on another and preferably opposite side thereof. Theportion 20 of circular cross-section is receivable within aperture 22 inthe depending arm I l of the bracket 6. Secured to the other end of thesheet [8 is a second sheet 24 having an aperture 26 therein in which therelief member D is mounted, the sheet 24 then having an offset portion28 of circular cross-section passable through aperture 30 in thedepending arm l6 of the bracket 6 and having its tip secured withinfingerpiece 32. In this way, the support I2 is pivotally mounted in thetone arm A and may be pivoted thereon through manipulation of thefingerpiece 32, the

latter constituting the moving mechanism- The front wall 4 of the tonearm A is cut away at 3A so as to permit movement of the fingerpiece 32.The depending arm N5 of the bracket t is provided with a pair of detents36, 36' (see Fig. 4) engageable with the fingerpiece 32 so as toreleasably hold it in either of' two positions displaced with respect toone another. In one of those positions, illustrated in-Fig. 2, thepickup unit B, suitable for use with conventional records, is inoperative or reproducing position, its needle 38 being verticallydisposed so as toengage the conventional record 40. In this position,the pick-up unit C, suitable for use with special or long playingrecords, is not in operative position, and the relief member D does notengage the record 40.

When the fingerpiece 32 is moved to its opposite position, illustratedin 1, 3 and 4, the' member D is moved to its record engaging position sothat it makes contact with the upper awn-.7122

surfaceiof the record 4ll 'andlthus relieves'sthe' rem-' ord'of someofthe weightoithe.pick-upsassembly; so that the force:exerted1ontherecordflflfi by-.the: needle381 is'lesslth'anthe forceexertediontherec+ rd 40 by the needle 38;

In order to accomplish this, thezresilientrelief memberDmay takeany oneoflazwide variety of forms solong as it. is capable of engaging thetop?- surface of a record when the pick-up unit C-is inoperativepositionand so long asit doesnoti engage the top surface of arecordwhenthepick up unit 3 is in operative position. It isalso es--sential that, when the member D does'engagethe: top-surface of a record,it resiliently acts there on in such a way as to relieve the needle 38*of the pick-up unit C of some of the'weight-of-the'pick up assembly. Tothisend, the tip 42 of 'the'member D must normally proj ect-beyond-the=tip of the needle 38' any suitable amount depending upon theresilience of the member D.

In the specific construction hereillustrated, the member D comprises a"sleeve dlpress-fi'tted or'otherwise secured in the-aperture 26 in theplate-28, this sleeve having flanges ita-t one-end thereof and a screwthreaded portion i 8-at-the* other end thereof: A- plunger genera-11ydesignate'd '50 is slidable-inthe sleeve 4-4; this plunger comprising afirst portion-52slidable between the fianges=46-and projectable outtherefrom, asec ond=portion 54' of greater diameter notpassable' throughtheflanges i'fi but slidable-within the sleeve "44; and a third portion56' of reduced di ameter'therea'bove. A spring 53 is positioned in sidethe sleeve 44; the bottom ofthe spring "acting upon the top-ofthe-second plungerportion El se as-to resiliently urge it downwardly-,-asviewed in Fig". 3, the top of the'spring'being engaged by screw 60adjustably receivable in the internally threaded portion' io"of'the'sleeve' 44; The farther the screw all is moved into the sleeve44, the more will the spring 58 'becompressed "and consequent- 1ythegreater will be the resilient-force exerted by the member D.

It is'preferre'd, in order to'preventbinding'of the plunger iifiwithinthe" sleeve 44; that the plunger EO'may'remain' in alignment With" thesleeve 4 i despite the 'transverse"forcesexerted' on". itby the'record4B. To this end the screwSil" is provided with an elongatedopen-bottomed aperture 62 into which the third plungerportion 56"isreceivable. It will be apparent from Fig: 3" that this construction willensure proper alignmentof 'the moving parts.

ltlisquite convenient to employ a spring 58"of" helicaliform, the bodyof'the spring thus encircling the third plunger portion 562 In such acase, it is desirable to provide a fourth plunger. portion 64 betweenthe second plunger portion 54" and. the third plunger portion56 andhaving a diameter intermediate those of the portions 54. and 56; thespace between the fourth plunger. portion 66 and the interior of thesleeve being-just sufficient to provide for free movement of the helicalspring 58 and the plunger 50. This sfourth plunger portion fi l acts asa supportandrg-uide for the spring 58, thus maintaining it, too, in axeial-alignmentwith the other parts.-

Once the screw 6i) has been set to-a position inwhich the resilience ofthe member D is.=as. desired, it may be locked in that position bymeansof the lock nut 66' shown in Fig. 3, or a spring strip 68'. securedat one end'lO to the sheet I2 as by. means of 1' the screw 12' andhaving 'ana frictional material.

screwa'fimis p'assable;..as illustrated in FigLimay server the;- same:purpose lnrorder tolassist inldistributing theiorce over'a;:.large.area. and at the. same time in order to '-2 improve thetracking of the tone arm A' over long playing records 405 and reducethetendency to skate,. it hasibeen found desirable toprovide the:projecting: end of 1 the; first plunger portion- 52Zwith.a pad-16 of.felt rubber, or other soft' By frictionally engaging a plurality of.groovesofthe. record il! simultaneousl-"y;. this pad 16:: will causethe tone arm A to travel. properly over the surface of the record- 49!"and'iwill also engage the terminal grooves of thatrecordiwith sufficientforce so as toensure the: operation of: whatever: automaticrecordchanger'tripping mechanism is employed.

The operation of thisipick-up assembly will inthesm'ain be apparentfromithe foregoing description. When it is desired to reproduceconventional.records,xthe fingerpiece 32 is rotated to its positionillustrated. in Fig. 2, at whichtime the needle 38 of the pick-up unit Bwill engage the conventional record 40 with the proper force, between.%and 11/2 ounces.

needle 38so that themember D will make no contact with th recordAO'. Iflong playing records are to be reproduced, the fingerpiece 32 is rotatedto its position illustrated in Figs. 1 and 4, at which time the pick-upunit B will be moved out of operative. position and the pick-up unit C Jwill be moved into i operative position so that'- the: needle 38' mayengage the groovesofthe At the'same time, the

long playing. record 40'; member D is positioned in itslrecord-engagingposition so that whenthe tone armis lowered onto therecord- -lt, the tip42 of the member D, since it projects belowthe tip of theneedle 38',

' will' make contact with the upper surface of the record ea before theneedle 38 makes contact.

In order for the needle 38- to reach the record 401'; itis necessarythatthe plunger 5!! slide upwardlyin the sleeve 44, resulting incompression" The spring 58 will therefore of: the spring. 58. exert aforce upon the surface ofthe record and theamount ofthat force will besubstracted from.

the normal force of to l -ouncesexerted by thetonearm assembly, theforce between the needle: 38.- and the record ll being the difierencebetween those two values. Thus, if the needle. 38 0f the conventionalpickup unit B exerts a force on the record'diiof 1 /2 ounces,

and ifitbedesired-that the needle 38 of the special pick-up unit C exerta force of only A ounce on thelong playing record iil, the screw will bescrewedinto the sleeve 44 so as to compress the spring 58- enough that,when the: plunger 56. is slid upwardly in the sleeve 44 a distance equalto the amount the tip of the plunger-'50extends below the tipof theneedle 38; thespring' 58 will exert a pressure on the plungerSll: andhence on the record 40' of 1 /1;- The resilience of the member D maybeadjusted whenthe pick-up assembly is in its position of Fig. 2, atwhich time the screw 60 is accessible from the underside of the tone armaperture M -in its otherzend:throughzwhichithe 753anditheforcebeingdistributed over-a largearea It will be notedthat'the-screw 60 is positoined above the tip of the 7. the-pressure is verylight. Moreover, the broad contacting surface providesfor improvedtracking and reduces the skating tendency inherent in pick-up unitsnormally associated with long playing records.

The pick-up assembly of the present invention is extremely simple, iscomposed of a relatively small number of parts, all of them easilyproduceable by mass production methods, is easily assembled, is positiveand adjustable in operation, and hence is particularly inexpensive andvaluable from a commercial point of view. In addition, the pick-upassembly may easily be placed in tone arms of the type already in use,it being necessary merely to remove the pick-up unit already in place insuch tone arms and insert the assembly of the present invention. In thisway. tone arms'now suitable for use only with conventional records canvery easily be converted into dual purpose tone arms.

While this invention has been here specifically described with respectto conventional and long playing records, it will be apparent that it isavailable for use in any application'whele different pressures are to beexerted upon records, as, for example, in combination recording andreproducing heads. Many variations may be made in the detailedconstruction of the apparatus all within the spirit of the invention asdefined in the following claims.

I claim:

1. A dual purpose pick-up assembly suitable for use with different typesof records comprising a tone arm, a pair of pick-up units mounted insaid tone arm so as to be movable one at a time into an operativeposition, each of said units having a needle projecting therefrom, and aresilient relief member mounted on said tone arm and operativelyconnected to one of said units so as to be moved therewith, said reliefmember comprising a non-vertically movable sleeve, 2, plunger slidabletherein and having a tip projecting therefrom, a spring within saidsleeve active on said plunger to urge it outwardly in the direction ofsaid tip, and means for adjusting the tension of said spring on saidplunger, the tip of said plunger extending beyond the needle in said oneof said units and being resiliently movable inwardly, said member beingmovable into record engaging position only when said one of said unitsis in operative position so that the tip of said plunger engages the topsurface Of a record and reduces the force exerted on said record by theneedle of said one of said units.

2. A dual purpose pick-up assembly suitable for use with two types ofrecords each requiring a different pick-up unit, said assemblycomprising a tone arm, a support articulately mounted in said tone arm,a first pick-up unit on one portion of said support and having a firstneedle depending therefrom, another pick-up unit' on another portion ofsaid support and having a second needle depending therefrom, and aresilient relief member secured to and projecting from said support,said relief member comprising a sleeve fixed to said support, a plungerslidable therein and having a tip projecting out therefrom on the sameside thereof as said second needle, a spring within said sleeve activeon said plunger to urge it outwardly in the direction of said tip, and'means for adjusting the tension of said spring on said plunger, the tipofsaid plunger extending beyond said second needle when said specialpick-up unit is inoperative position but being resiliently movable, in-

wardly, said tip engaging the top surface of a.

record only when said other pick-up unit is in operative position andreducing the force exertedv by said second needle on said record.

3. A dual purpose pick-up assembly suitable for use with two types ofrecords each requiring. a different pick-up unit, said assemblycompris-,

ing a tone arm, a bracket secured thereto, a support pivotally mountedin said bracket, 3, first pick-up unit on one side of said support andhaving a first needle depending therefrom, another pick-up unit onanother side of said support and having a second needle dependingtherefrom, and a resilient relief member secured to and projecting fromsaid other side of said sup port, the tip of said member extendingbeyond said second needle but being resiliently movable toward saidsupport, said tip engaging the top surface of a record when said otherpick-up unit is in operative position and reducing the force exerted bysaid second needle on said record.

4. A dual purpose pickup assembly suitable for use with two types ofrecords each requiring a different pick-up unit, said assemblycomprising a tone arm, a bracket secured thereto, a, support pivotallymounted in said bracket, a first pick-up unit on one side of saidsupport and having a first needle depending therefrom, an-

up unit is in operative position and reducing the force exerted by saidsecond needle on said rec- 0rd.

5. The dual purpose pick-up assembly of claim 2, in which said sleevehas a flange at its bottom and internal threads at its top, said plungercomprising, in order, a first portion slidable between said flanges andterminating in a tip, and a second portion of larger diameter slidablein said sleeve but not passable between said flanges, the bottom of saidspring engaging the top of'said second plunger portion, and in which ascrew is threadable into the top of said sleeve so as to engage the topof said spring and adjust its tension.

2, in which said sleeve has a flange at its bottom and internal threadsat its top, said plunger comprising, in order, a first portion slidablebetween said flanges and terminating in a tip, a second portion oflarger diameter slidable in said sleeve but not passable between saidflanges, and a third portion of smaller diameter, the bottom of saidspring engaging the top of said second plunger portion, and in which ascrew having an openbottomed aperture is threadable into the top of saidsleeve so as to engage'the top of said spring and adjust its tension,said third plunger portion being receivable inside said open-bottomedap--- erture as said screw is threaded into said sleeve.

'7. .A resilient relief member for use on a tone armand engageable witha record comprising a sleeve secured to said tone arm, said sleevehaving a flange at its bottom and internal threads at its top, a plungerslidable in said sleeve, said plunger comprising, in order, a firstportion slidable between said fianges and terminating in a tip,: asecond portion of larger diameter slidable 6. The dual purpose pick-upassembly of clainr 9 in said sleeve but not -'passable between saidflanges, and a third portionzof smaller diameter,

.aarzspringainzsaid.sleeve.the:bcttom of which engages the 'top.ofisaidsecond :plunger portion and "the bothof which .encirclessaidthird aplunger portion, and a .screw having ,an open bottomed zraperturethreadablerinto the top of said-sleeve :and engaging ,the,top ofsaid;spring to adiustits itension, said third plungerrp.ortionbeingreceiv- :able in:said open-bottomed aperture assaid screw is:threaded into said .sleeve.

A dual purpose .pick-up assembly suitable for use with different typesof records comprising a tone arm, a pair of pick-up units mounted insaid tone arm so as to be movable one at a time into an operativeposition, each of said units having a needle projecting therefrom, and aresilient relief member mounted on said tone arm and operativelyconnected to one of said units so as to be moved therewith, said reliefmember comprising a non-vertically movable sleeve, a plunger slidabletherein and having a tip projecting therefrom, and a spring within saidsleeve active on said plunger to urge it outwardly in the direction ofsaid tip, the tip of said plunger extending beyond the needle in saidone of said units and being resiliently movable inwardly, said memberbeing movable into record engaging position only when said one of saidunits is in operative position so that the tip of said plunger engagesthe top surface of a record and reduces the force exerted on said recordby the needle of said one of said units.

9. A dual purpose pick-up assembly suitable for use with two types ofrecords each requiring a different pick-up unit, said assemblycomprising a tone arm, a support articulately mounted in said tone arm,a first pick-up unit on one portion of said support and having a firstneedle depending therefrom, another pick-up unit on another portion ofsaid support and having a second needle depending therefrom, and aresilient relief member secured to and projecting from said support,said relief member comprising a sleeve fixed to said support, a plungerslidable therein and having a tip projecting out therefrom on the sameside thereof as said second needle, and a spring within said sleeveactive on said plunger to urge it outwardly in the direction of saidtip, the tip of said plunger extending beyond said second needle whensaid other pick-up unit is in operative position but being resilientlymovable inwardly, said tip engaging the top surface of a record onlywhen said other pick-up unit is in operative position and reducing theforce exerted by said second needle on said record.

10. A dual purpose pick-up assembly suitable for use with two types ofrecords each requiring a different pick-up unit, said assemblycomprising a tone arm having an open bottom and a substantially U-shapedcross section, thus defining an open-bottomed housing, a bracket securedto the inside of said tone arm, a support mounted in said bracket andinside said tone arm so as to be pivotable about an axis substantiallyparallel to the plane of said tone arm, a first pick-up unit on one sideof said support and having a first needle depending therefrom, anotherpick-up unit on another side of said support and having a second needledepending therefrom, and a resilient relief member secured to andprojecting from said other side of said support, the tip of said memberextending beyond said second needle but being resiliently :movabletoward said support, said tip engag- 'ing thetop surface-ofa-record'when'saidother pick-upunitis inoperativeposition and reducingthe force exerted 'by said second needle on said record, said first"pick-up unit being housed -within 'saiditone-arm" when the supportispositioned 'so that said other pick-up unit is. op-

erativeposition, .and vice versa.

11. A dualpurpose pick-up assembly suitable for use with-wrotypes .ofrecords each requiring a different pick-up unit, said assemblycomprising a tone -arm having an open bottom and a substantiallyU-shaped cross sectionythus'defining an open bottomed housing, a bracketsecured to the inside of said tone arm, a support mounted in saidbracket and inside said tone arm so as to be pivotable about an axissubstantially parallel to the plane of said tone arm, a first pick-upunit on one side of said support and having a first needle dependingtherefrom, another pick-up unit on the opposite side of said support andhaving a second needle depending therefrom, and a resilient reliefmember secured to and projecting from said opposite side of saidsupport, the tip of said member extending beyond said second needle butbeing resiliently movable toward said support, said tip engaging the topsurface of a record when said other pickup unit is in operative positionand reducing the force exerted by said second needle on said record,said first pick-up unit being housed within said tone arm when thesupport is positioned so that said other pick-up unit is in operativeposition, and vice versa.

12. A dual purpose pick-up assembly suitable for use with two tvpes ofrecords each requiring a different pick-up unit, said assemblycomprising a tone arm having an open bottom and a substantially U-shapedcross section, thus defining an open bottomed housing, a support mountedinside said tone arm so as to be pivotable about an axis substantiallyparallel to the plane of said tone arm, a first pick-up unit on one sideof said support and having a first needle depending therefrom, anotherpick-up unit on another side of said support and having a second needledepending therefrom, and a resilient relief member secured to andproiecting from said other side of said support, the tip of said memberextending beyond said second needle but being resiliently movable towardsaid support, said tip engaging the top surface of a record when saidother pick-up unit is in operative position and reducing the forceexerted by said second needle on said record, said first pick-up unitbeing housed within said tone arm when the support is positioned so thatsaid other pickup is in operative position, and vice versa.

13. A dual purpose pick-up assembly suitable for use with two types ofrecords each requiring a different pick-up unit, said assemblycomprising a tone arm having an open bottom and a substantially U-shapedcross section, thus defining an open bottomed housing, a support mountedinside said tone arm so as to be pivotable about an axis substantiallyparallel to the plane of said tone arm, a first pick-up unit on one sideof said support and having a first needle depending therefrom, anotherpick-up unit on the opposite side of said support and having a secondneedle depending therefrom, and a resilient relief member secured to andprojectlng from said opposite side of said support, the tip of saidmember extending beyond said second needle but being resiliently movablesaid first pick-up unit being housed within said tone arm when thesupport is positioned so that said other pick-up unit is in operativeposition,

and Vice versa.

, BERNE N. FISHER.

REFERENCES CITED -The following references are of record in the .1111;of this patent:

Number 12 UNITED STATES PATENTS Name 7 Date Edison June 14, 1898 RousselFeb. 21, 1905 Holland Dec. 31,1912 Holland Oct. '5, 1915 Holland Nov. 5,1918 Kellum Feb. 18,1919 Kramer Nov; 16, 1926 Head Aug. 30,;1'932 KohlerJune 27, 1933 Ressler Juli 31, 1955

